For anyone with a serious interest in the history of marijuana prohibition, Isaac Campos has made an indispensable contribution to the literature with Home Grown, his scholarly work on the history of marijuana in Mexico. In so doing, he not only opens up a previously neglected area of marijuana research -- Mexico! -- but also makes a compelling case for a revisionist view of the standard narratives of pot prohibition in the United States.

Relying on archival research, access to thousands upon thousands of Mexican press articles over more than 150 years, and the latest social science insights into the social and cultural construction of narratives about drug use, as well as some groundbreaking Mexican intellectual and scientific history, the University of Cincinnati historian covers the career of marijuana in Mexico from its introduction by Spanish colonists shortly after Conquest through its prohibition throughout nationwide by the new revolutionary government in 1920.

Campos traces marijuana's arrival in Mexico to at least as far back as 1530, when one of the conquistadors was granted royal approval to import it for hemp farming. Back then, it was known as canamo, the Spanish word for cannabis. Hemp farming never really took off in Mexico, but the plant itself, a native of Southwest Asia, certainly went native, so to speak.

And that was part of pot's problem. While efforts to farm hemp had largely died out by the beginning of the 19th Century -- mainly for lack of reliable seed supplies -- knowledge of the plant spread during the colonial era among Mexico's indigenous population, which was already well-versed in the use of a wide variety of herbs and plants, including psychoactive ones. Indigenous medical and spiritual practices, which were closely tied, ran afoul first of the Inquisition, which tried to suppress them as the devil's work, and later, of modernizing Mexico, which wanted to shun its "primitive" or "degenerate" indigenous heritage for "civilized" European status.

Campos notes the first report of smoking marijuana for its psychoactive effects in 1846. By then, the plant had been thoroughly Mexicanized, so much so that it was considered indigenous and its introduction as cannabis forgotten. In fact, many observers didn't even realize that the demon weed, now becoming known as "marijuana" was the same plant as cannabis.

As Campos shows in painstaking historical detail, over the next century and a half, marijuana developed a reputation as a bringer of madness and violence, a view that was widely shared both by the indigenous masses and scientific and medical scholars. Newspaper reports of marijuana were almost exclusively and unanimously about people who had smoked it, then committed horrid crimes of violence while driven insane by its pernicious effects. Peasants were known to scream in terror or make the sign of the cross at the mere sight of the plant, associated as it was not only with madness, but with indigenous witchery.

Throughout the 19th Century, there was no counter-narrative to Mexican reefer madness (in fact, when one Mexican physician dared to challenge the orthodox view in 1938, he was nearly drummed out of the profession amid great scandal). Marijuana made you crazy, and the only people who smoked it were criminals, prisoners, and soldiers in barracks. That was the common wisdom, and it was universally supported by the science of the day.

Since running amok on weed seems so foreign to our cultural experience with the drug, Campos devotes some effort to explaining why the reports of madness and mayhem were so consistent. Did it actually make people go crazy? Here he delves into set and setting, the social construction of drug use, and the modern of science of marijuana to suggest that while people may have occasionally really rampaged on reefer, it is more likely that the reports conflated marijuana and other drug use, especially alcohol; that the existing narratives created a sort of "placebo effect" where people did what was expected of them -- go crazy on weed -- that the reports were sometimes made up to sell newspapers, and that because Mexican law provided a sort of insanity defense for people who were intoxicated, people claimed to have been under the influence to avoid criminal sanctions for their crimes.

By the late 19th Century, the repression of marijuana was underway in Mexico. First came restrictions on the sale of marijuana at herbolarias, the market herb stalls operated by indigenous women (you can still see them at the Sonora witches' market in Mexico City), then state and local bans, and in 1920, national marijuana prohibition in Mexico.

Campos' history of marijuana in Mexico is fascinating in its own right and is an outstanding contribution to the literature in itself, but he makes a real contribution to our understanding of pot prohibition in the US as well. The standard narrative, laid down by Bonnie and Whitebread in The Marijuana Conviction and Musto in The American Disease, and relied on by most later scholars, is that Reefer Madness was largely fueled by prejudice and racism toward Mexicans and their drug.

Campos shows that while anti-Mexican sentiment indeed played a role in the construction of the Reefer Madness narrative, that narrative was as much a Mexican import as the weed itself. Mexican public and scientific opinion fully embraced the "marijuana is madness" meme, English-language Mexican newspaper reports of pot atrocities were reprinted widely in the US -- sometimes the same Mexican press story would circulate for years in the US, being reprinted at different times by different newspapers, often with sensational embellishments. Mexico delivered a nicely-wrapped, full-blown Reefer Madness narrative into the eager arms of the likes of Harry Anslinger, who would use it as the basis of our very own version of Reefer Madness.

And that means we have to revise the standard narrative on the history of pot prohibition in the US. We didn't cram marijuana prohibition down Mexico's throat; the Mexicans did it themselves, and the process began long before the US began trying to impose its prohibitionist views on the rest of the world. And, as Campos makes abundantly clear, blaming it on racism directed at Mexicans is just too simple.

Home Grown is a most welcome and important contribution to the history of marijuana prohibition. It has broadened our understanding of how we got to this place, and it belongs on the book shelf of every serious student of the topic.